Apparatus for handling spinning solutions



Nov. 14, 1944. LR SPANGLER ErAL, 2,362,674

APPARATUS FOR HANDLING SPINNING SOLUTIONS Filed Oct. 4. 1941 "F5 ZA n v2 n n w A a1. a 2- INVENTOR, LYNW/LL KELSEYEPANELER BY Hwum Ecuvmu PRATTPatented Nov. 14, 1944 APPARATUS FOR HANDLING SPINNING' SOLUTIONSLynwill Kelsey Spangler and Harold Conrad Pratt, Parkersburg, W. Va,assignors to American Viscose Corporation, Wilmington, Del., a

corporation of Delaware Application October 4, 1941, Serial No. 413,578

8 Claims. (Cl. 18-8) 4 This invention relates tothe handling of unstablechemical dispersions such as are employed in spinning artificialfilaments, The invention is particularly concerned with the problem ofreducing non-uniformity of viscose or other spinning solutions to bedelivered to the spinning machines.- Such solutions or dispersions areprepared by a procedure including steps of ageing or ripening undercarefully controlled conditions, filtering and blending after which theyare led into a set of supply tanks. The viscose dispersions, each havingthe'desired ripeness, are led into the empty tanks of the set inpredetermined order while the full tanks of the set are discharging,usually one at a time, in corresponding order so that the viscosesupplied to the spinning machine is substantially uniform in ripeness,

and hence in chemical and physical and more particularly inviscosity.

However, it is the practice in emptying any given tank to leave a smallpart of the viscose in the bottom thereof in order to prevent theentraining of air bubbles in the viscose as it is discharged from thetank. The air bubbles would be entrained by virtue of the tendency ofthe viscose to form a vortex in the last portion to be properties,

removed, and the amount of the viscose necessary to be left in the tankin order to prevent any entrainment of air is quite large, especially intanks whose bottoms are formed in the shape of relatively shallow cones.

This residual viscose left in the bottom of the tank, the so-called"heel or tankbottom," undergoes further ripening so that its ripeness isconsiderably advanced with respect to that of the next batch of viscosewith which the tank is to be filled, and, in the large proportions thatsuch bottoms have heretofore been left in such tanks, the heel does notbecome mixed to any substantial extent within the new batch of viscose.Because of the fact that the final physical char- 1 acteristics of thefilamentary material depend upon the uniformity of the ripeness of theviscose or other solution from which it is spun, it is highly desirableto reduce as far as possible the amount of heel or tank bottom that isnecessary to be left within any given supply tank.

"The amount of heel to be left has heretofore been reduced somewhat bythe practice of opening the next supply tank tethepump as soon as thelevel in any given supply tank being dischargedby the pump becomesdangerously low, but this procedure is inadequate so that quite asizeable mains as a heel.

quantity of viscose still re- It is an object of the invention toprovide a novel method by which most of the heel is removed from anygiven-supply tank slowly at a positively controlled rate withoutpermitting entrance of air into the material being discharged andwithout aifecting the uniformity of delivery rate to the spinningmachines. It is a further object of the invention to provide a novelarrangement of apparatusto effectuate the removal of the heel in themanner hereinafter described. Further objects of the invention willappear from the description thereof.

In-the drawing, which is of a diagrammatic character, 15

Figure 1 shows one embodiment of the invention, 7

Figures 2 to 5 inclusive show successive steps in a second embodiment ofthe invention, and

Figure- 6 shows a variation in the modification of Figures 2 to 5inclusive. 7

For purposes of illustration, the description of the drawing hereinafterwill refer specifically to the handling of viscose, but it is to beunderstood that the apparatus and procedure is applicable generally tothe handling of other chemical solutions-or dispersions presentingsimilar problems. a

In Figure 1, there is shown diagrammatically a spinning set of sixsupply tanks for viscose, which are numbered in the order of dischargeor withdrawal of their contents by the main pump to the spinningmachine. Each of the supply tanks is provided with a connection to acompressed air line la, each of such connections being controlled by thevalves 8, 9, III, II, I2 and I3. These air valves may all be openconstantly (except during filling of a tank when its valve willordinarily be closed and the tank vented to the atmosphere) or they maybe opened only to the respective tanks as they or their heels are beingemptied and it is to be presumed that either of these conditions existsin the following description. The air pressure thereby assists the pumpsin discharging the tanks.

The respective supply tank are connected to a ring or loop header It bymeans of the three-way valves l5, l6, l1, l8,.l9, and 20. This loop orring header is connected by the pipe 2| to the pump 22 which dischargesinto the pipe 23 leading to the spinning machines. ment so far describedhas been in common use heretofore. In accordance with the invention, therespective supply tanks are connected to an auxiliary header 24 and anauxiliary pump 25 which discharges into the suction side of the Thearrangemain pump 22. The flow oi. the contents of the supply tanksthrough the auxiliary header 24 is controlled by the valves 26, 21, 2s,29, an and so that large amounts of viscose will not beretained by theauxiliary lines between their.

intervals of operation.

In operation, valves 26, 21, 28, 29, 30, and 3| are normally closedwhile the main body of any given tank, such as I, is being discharged.In

' r the normal operation of delivery, the three-way valve I5 of supplytank I is turned so as to open the supply tank connection into theheader I4 while the three-way valves on the other supply tanks areblanked toward the respective tanks; in this way, the viscose in supplytank I is fed to the pump through both branches of the ring header I4.When the viscose in supply tank I has become relatively low and hasattained a predetermined level, the three-way valve I6 on the next tank,supply tank 2, is turned to open the connection of that tank into thering header I4, and either directly thereafter or at any time before thesupply tank I approaches a dangerously low level where it tends to drawair into the lines, the three-way valve I5 is blanked toward tank I, thevalve 28 is opened and the auxiliary pump 25 is operated so that thecontents of supply tank I are discharged into the line at a much slowerrate than would be possible were it connected directly to the main pump22, so that most of the heel in supply tank I is discharged into thespinning line without entraining air therein. This permits of thedischarge of the supply from any given tank to a far greater extentwithout entraining air than was heretofore possible and correspondinglyreduces the heel so that subsequent filling of the tank results in muchgreater uniformity of the contents therein. Tank I is then filled withthe next batch of viscose and the cycle just described is repeated foreach of the tanks in succession as they are emptied. A valve 32 isprovided in the air line Ia and is normally closed, though if additionalsupply tanks or sets of tanks are connected to the air line it may beopened to them.

In Figure 2 to 5 inclusive, a modified arrangement is shown in which thesupply tanks of a spinning set numbered in the drawing in their order ofdischarge are connected as before to an air supply line Ia by the valves8,v 8, III, II, I2,

and I3 and to a ring header I4 by means of the three-way valves I5, I8,I'I, I8, I9, and 20. The ring header I4 is connected by pipe 2I to themain pump '22 which discharges into the pipe 23 leading to the spinningmachines. In accordance with the modified embodiment of the invention,the auxiliary pump 25 of relatively small discharge rateas compared tothe main pump is connected across the ring header I4 so as to di-, Videthe supply tanks connected thereto into two equal groups. This auxiliarypump connection is. also supplied with the valve 33 for connecting anddisconnectingthe suction side of the auxiliary pump to the ring header.

Figure 2 shows the operation while emptying the main bulk of the supplyin tank I during which valve 33 is closedwhile valves I8, II, I8,

I18, and 20 are blanked toward their respective:

supply tanks in order to permit theviscose from 15 t each of m tanks,valve means for controlling tank I to flow through valve I5 into bothbranches of the ring header I4 to the pump 22.

when the viscose in tank I approaches a predetermined low level, valveI8 is turned in order to connect tank 2 to the header I4, as shown inFigure 3. Valve I8 connected to tank 2 is then blanked toward theauxiliary pump connection as shown in Figure 4 so that viscose from tank2 flows only through the right branch of the ring header I4 to the pump22. At the same time or immediately thereafter valve I5 is blankedtoward th main pump and turned so as to connect tank I to the auxiliarypump line in which valve 33 isopened and the auxiliary pump 25 started.In this manner the main pump 22 is supplied chiefly from supply tank 2while drawing a small amount from tank I as controlled by the auxil- Iiary pump 25.

When the viscose in tank I has reached the lowest permissible level,pump 25 is turned 01!, valve 33 is closed, valve I5 is blanked towardviscose tank I, and valve I8 is turned to connect supply tank 2 to bothbranches of the ring header I4 (all as shown in Figure 5), and tank Imay be refilled, after which the cycle is repeated for each successivetank.

Figure 6 shows a modification of the embodiment of the invention shownin Figures 2 t0 5 which is necessary when an odd number of supply tanksconstitute a spinning set. As shown in Figure 6, the auxiliary pump isprovided with a conduit having two connections 34 and 35 to the ringheader I4 on either side of the middle tank I. These two connections arenecessary in order to block off the central tank I exclusively to one orthe other of the pumps when either tank I or tank 6 is blocked ofiexclusively to the. other pump. Oneor the other of the two valves areshown in the drawing. While it has been stated that the pumps dischargeinto lines leading to spinning machines, these pipes may, it desired,first proceed to other processing devices, such as filters, beforeentering the spinning machines. The several supply tanks may be providedwith the customary thermometer wells and pressure gages, and also withsight glasses at any desired levels or with signaling devices toindicate when designated or predetermined levels are reached by theviscose in the tank. If desired, the auxiliary and main pumps may beconnected to separate motors or to a common motor, suitable reductiongearing being supplied in the latter case to adapt the motor. to theoutputs desired of the two pumps.

While a preferred embodiment of the inven- -tion has been disclosed, thedescription is in- .tended to be illustrative only, and it is to beunderstood that changes and variations may be made without departingfrom the spirit or scope of the invention as defined by the appendedclaims.

the flow of the contents of each of said tanks through said header, anauxiliary header connected to each of said tanks, valve means forcontrolling the flow of the contents of each of said tanks through saidauxiliary header, means connecting said auxiliary header to said mainheader, and pumping means for controlling the flow through saidconnecting means.

2. In apparatus of the class described, a plurality of supply tanks, aring header connected to each of said tanks, valve means for controllingthe fiow of the contents of each of said tanks through said header, anauxiliary header connected to each of said tanks, valve means forcontrolling the flow of the contents of each of said tanks through saidauxiliary header, means for uniting the efliuents from each header, saidlast-mentioned means comprising a pump for controlling the rate of flowfrom said auxiliary header.

3. In apparatus of the class described, a plurality of tanks, a mainheader connected to each of said tanks, valve means for controlling theflow of contents from each of said tanks through said header, a conduitconnected to said header between two of said tanks to divide the tanksinto two groups, pumping means in said conduit and means for uniting thedischarge of said pump with the discharge from said header.

4. In apparatus of the class described, a plurality of tanks, a mainheader connected to each of said tanks, valve means for controlling theflow of contents from each of said tanks through said header, a conduitconnected to said header between two of said tanks'to divide the tanksinto two approximately equal groups, pumping means in said conduit andmeans for uniting the discharge of said pump with the discharge fromsaid header.

5. In apparatus of the character described, a plurality of tanks, 9.ring header connected to each of said tanks, a conduit connected to saidheader between two of said tanks to divide the tanks into two groups,pumping means in'said conduit, valve means for directing the flow fromany of the tanks through the header away from said connection and valvemeans for directing the flow from any of the tanks on the opposite sideof said connection exclusively toward said connection.

6. In apparatus of the character described, an even number of tanks, aring header connected to each of said tanks, a conduit connected to saidheader between two of said tanks to divide the tanks into two equalgroups, pumping means in said conduit, valve means for directing theflow from any of the tanks through the header away from said connectionand valve means for directing the flow from any of the tanks on theopposite side of said connection exclusively toward said connection.

'7. In apparatus of the character described a plurality of tanksconstituting an odd total number, a ring header connected to each ofsaid tanks, a conduit connected to said header at both sides or itsconnections to the central tank thereby dividing the remainder of thetanks into two equal groups, pumping means connected to said conduit andvalve means in said conduit for selectively connecting said pumpingmeans to either side of said central tank, means for directing the flowfrom any of the tanks through the header away from said selectiveconnection, and valve means for directing the flow from any of the tankson the opposite side of said selective connection exclusively towardsaid connection, and means for uniting the discharge of said pump withthe discharge from said header.

8. In apparatus of the class described, a plurality of supply tanks, amain header connected to each or said tanks, valve means for controllingthe flow of the contents or each of said tanks through said header, anauxiliary header connected to each of said tanks, valve means forcontrolling the flow of the contents of each of said tanks through saidauxiliary header, means connecting said auxiliary header to said mainheader,'- and means for controlling the flow through said connectingmeans.

LYNW'ILL KELSEY SPANGLER. HAROLD CONRAD PRATT.

